I was able to resolve my problem by following these instructions provided by
Dell Technical Support:

1. As soon as you turn on the system, tap-tap F8 key on the keyboard.
2. Highlight the option for SAFE MODE and then press enter.
3. Once in SAFE MODE, click on Windows Logo and then type SYSTEM RESTORE in
Start Search.
4. Click on SYSTEM RESTORE, follow the onscreen instructions, uncheck the
option for "Do not show restore older than 5 days" and restore the system
back to a date when it was working fine.

Good luck!!!

"Websitespider" wrote:
[color=blue]
>
> I have the same problem except mine occurred after I decided to add a
> 'Visitor' account. I have several people coming for Christmas and some of
> them are bound to want to use the PC to access the internet and their emails
> etc.
>
> I have added a new user called 'Visitor' but when I try to login into the
> newly set up account I get the message 'The User Profile Service service
> failed this logon', I have checked the registry re
> HKLM\Software\Microsoft\Windows NT\Current
> User\ProfileList\ and was unable to find the new user listed there.
>
> I certainly don't want to restore my PC to when I purchased it so can anyone
> help, PLEASE!!!!
> "Mr. Home Compter Man" wrote:
>[color=green]
> > My new Dell computer running Vista Home Premium was working fine for about
> > two weeks. Now I can't logon and receive the message that "user profile
> > cannot be loaded." I can't receive any support form Microsoft because I
> > can't access my ID number for Vista Home Premium. I contacted Dell but so
> > far haven't received any solution to this problem.
> >
> > I did find on Dell Support community forum Article ID 316063 dated
> > 12/17/2007 that seemed to address this problem. It gave a step-by-step
> > listing to perform a System Restore in the Window Recovery Environment. Can
> > someone confirm whether this listing is the way to resolve this logon
> > problem? Thanks.[/color][/color]